1. Field of the Invention
The present invention relates to a battery which is preferable to be used for devices such as mobile terminals, and particularly relates to a battery which is provided with a circuit board.
2. Description of Related Art
Conventionally, a battery for a mobile terminal such as a mobile phone, has been known. Further, a battery having a battery cell to which various circuit boards such as a protection circuit that deals with an overcharge, for example, has been provided. In a general sense, the circuit board has been adhered to the battery cell by molded resin so as to form one entire unit which would improve handling accommodation and prevent conflicts regarding industrial design.
FIGS. 4 to 6 are examples of a conventional battery. In FIG. 4, reference numeral 1 indicates a battery cell, and reference numeral 2 indicates a molded section. Battery cell 1 is formed in a rectangular shape so as to have a constant thickness, with most of the battery cell covered by aluminum casing 3. Aluminum casing 3 forms an anode, and a cathode which is formed on one side of casing 3 (not shown in the drawing).
As shown in FIGS. 5 and 6, circuit board 5 is mounted on side surface 4 of battery cell 1. Circuit board 5 is formed by mounting various electronic units 7 on board 6. Circuit board 5 is attached to battery cell 1 by positioning board 6 in parallel with side surface 4 and adhering the back surface of board 6 to side surface 4 by double-face sticking tape 8.
Circuit board 5 and battery cell 1 are connected electrically by electrode terminal 10. That is, output terminal board 12 is fixed on side surface 11 of casing 3 of battery cell 1. Input terminal 13 is disposed on an upper surface of an edge of board 6. A space between output terminal board 12 and input terminal board 13 is connected by electrode terminal 10.
Electrode terminal 10 is formed by bending a strip of conductive board. Electrode terminal 10 comprises fixed section 14 of one end of which is fixed on output terminal board 12, extracted section 15 which is bent orthogonally along the side shape of casing 3 from fixed section 14 while contacting side surface 4 and extending along side surface 4, bent section 16 which is bent in a direction from extracted section 15 towards the far side of side surface 4, and fixed section 17 which extends along board 6 from bent section 16 and fixed on input terminal 13. The above explained electrical configuration describes the case of an anode region. The cathode region has an equivalent structure wherein battery cell 1 and circuit board 5 are connected.
Circuit board 5 and electrode terminal 10 are embedded in molded section 2. Circuit board 5 and electrode terminal 10 are attached to battery cell 1 so as to form an entire unit by molded section 2. That is, in the battery, circuit board 5 and electrode terminal 10 and the like are assembled to battery cell 1, and circuit board 5 and electrode terminal 10 are molded so as to be embedded in a resin, and molded section 2 made of the resin is formed to be an entire unit with battery cell 1.
Also, power supply output from battery cell 1 and circuit board 5 is extracted from connector 19 via output cable 18 as shown in FIG. 4.
In a case of the above battery, when performing molding to battery cell 1, a region where adhesion strength between battery cell 1 and molded section 2 cannot be obtained sufficiently is generated. Thus, there is a problem that a part of molded section 2 might be scraped off from battery cell 1 after production.
In the above battery, extracted section 15 of electrode terminal 10 contacts side surface 4. Thus, the position of electrode terminal 10 is close to side surfaces 4 and 11 of battery cell 1. Therefore, the resin cannot go between electrode terminal 10 and side surfaces 4 and 11 when performing molding. In such a region, the area which is required for adhesion of molded section 2 to side surfaces 4 and 11 becomes insufficient. Therefore, the adhesion strength of such a region becomes insufficient, and it is a problem that an area in molded section 2 as shown by reference numeral 20 in FIG. 4 could get scraped off.
Additionally, in the above battery, when molded section 2 is scraped from battery cell 1, such a product cannot be delivered as commercial goods. Also, it is difficult to disassemble such products for the purpose of reuse from a cost point of view, because of bad yield of battery production, and more importantly because of a huge financial loss.
The present invention was made in consideration of the above situation and disadvantages. An object of the present invention is to provide a battery which can adhere a molded section to a battery cell tightly in a battery in which a circuit board and an electrode terminal are adhered to a battery cell so as to form an entire unit by performing molding.